The present invention relates to illumination of the control knob of a dimmer device and more particularly, to the structure by which a dimmer device is reliably and economically assembled with a means for illuminating the control knob of the dimmer to a degree which permits it to be found in the dark.
It has been known for many years that in homes and other buildings where a person enters a darkened room, it is advantageous to have a minimum level of light at locations within the room where control operations are performed, and particularly the control which illuminates the room itself. Switches of the toggle mechanism variety have illuminated triggers so that one of these switch triggers appears as a point of light to a person entering an otherwise darkened room. Such switches have been known for many years and a number of patents have been issued covering such structures. U.S. Pat. Nos. such as 2,625,631 and 3,701,870 for example are concerned with switch mechanisms which have illuminated activators. Further, on equipment such as television sets, electric cooking ranges, washing machines and the like, the control mechanism of such apparatus is frequently illuminated to provide an indication that the apparatus is in the electrically active state. U.S. Pat. Nos. such as 2,732,467; 2,339,904; 2,548,760 typify the type of apparatus which have illuminated controls.
Dimmer products have appeared on the market which provide illumination of the control for a dimming device. Such articles have had glow lamps mounted beneath a dimmer knob to deliver light through a wall bracket to the underside of the dimmer knob. As is known, many dimmers have controls which are operated by two essentially independent motions. For such devices, the ON-OFF switching motion is operated by a pushing of a shaft into the dimmer device to operate a mechanism within the device and to switch the current ON or to switch it OFF. Independently of this motion, the dimmer is equipped to undergo a rotary control motion and this rotary control serves to establish the level of electric power which flows through the dimmer switch. Accordingly for such devices, it is feasible to turn some dimmers ON by their push-On, push-Off, switching motion at any lighting level to which the rotary control knob happens to be turned when the ON-OFF switch is activated. Alternatively an ON-OFF activation may be incorporated in a purely rotary switch at the end of the rotary control motion of the control knob and its associated control shaft.
A problem which relates to the illumination of many dimmer devices is that the control element is a rather substantial knob which is spaced from the switch housing at the end of the control shaft, and the shaft undergoes both reciprocal in and out motion and rotary lighting level control motion. Accordingly, the control element of such dimmers is substantially larger than the conventional toggle trigger which protrudes through the switch plate opening of the conventional switch structures and wall plate structures.
Another problem which concerns the illumination of the dimmer control mechanism is that the structure within the dimmer apparatus itself is quite complex when compared for example, to the conventional ON-OFF switch. There is a circuit in the dimmer housing which is the control circuit for the dimmer and this is the circuit which is operated by the manipulation of the control knob. Typical patents which describe the internal structure of such switches are U.S. Pat. No. 3,103,618 and others.